פירוש על מלכים א 1:5

Exalted himself. He elevated himself.⁹The literal meaning is, “lifted himself.”

And he prepared him chariots and horsemen, and fifty men to run before him: It is fitting for you to know that it was not permitted for the kings of Israel to accumulate many horses (Deuteronomy 17:16), and therefore this was not a small matter for the kings of Israel.

And fifty men. Whose spleens had been removed, and whose soles of their feet had been carved.¹⁰See Maseches Sanhedrin 21b and Rashi there.